syzbot


KASAN: out-of-bounds Write in end_buffer_read_sync

Status: upstream: reported syz repro on 2023/05/29 19:57
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+a4e609731ea45e9086d3@syzkaller.appspotmail.com
First crash: 332d, last: 22d
Bug presence (2)
Date Name Commit Repro Result
2023/05/29 upstream (ToT) 8b817fded42d C [report] KASAN: out-of-bounds Write in end_buffer_read_sync
2024/04/15 upstream (ToT) 0bbac3facb5d C Failed due to an error; will retry later
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: out-of-bounds Write in end_buffer_read_sync ntfs3 C done 2528 1h07m 731d 0/26 upstream: reported C repro on 2022/04/25 03:07
linux-5.15 KASAN: out-of-bounds Write in end_buffer_read_sync origin:lts-only C error 36 4d18h 387d 0/3 upstream: reported C repro on 2023/04/04 06:42
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/03/20 02:16 3h00m bisect fix linux-6.1.y job log (0) log
2024/01/04 10:55 1h56m bisect fix linux-6.1.y job log (0) log
2023/12/04 05:39 1h49m bisect fix linux-6.1.y job log (0) log

Sample crash report:
==================================================================
BUG: KASAN: out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:257 [inline]
BUG: KASAN: out-of-bounds in put_bh include/linux/buffer_head.h:320 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xbd/0xd0 fs/buffer.c:160
Write of size 4 at addr ffffc90003ba7820 by task ksoftirqd/1/21

CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.30-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:257 [inline]
 put_bh include/linux/buffer_head.h:320 [inline]
 end_buffer_read_sync+0xbd/0xd0 fs/buffer.c:160
 end_bio_bh_io_sync+0xb3/0x110 fs/buffer.c:2655
 req_bio_endio block/blk-mq.c:763 [inline]
 blk_update_request+0x53b/0x1010 block/blk-mq.c:908
 blk_mq_end_request+0x3a/0x70 block/blk-mq.c:1035
 blk_complete_reqs block/blk-mq.c:1113 [inline]
 blk_done_softirq+0xf8/0x140 block/blk-mq.c:1118
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571
 run_ksoftirqd+0xc1/0x120 kernel/softirq.c:934
 smpboot_thread_fn+0x51b/0xa10 kernel/smpboot.c:164
 kthread+0x26e/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc90003ba0000, ffffc90003ba9000) created by:
 copy_process+0x637/0x4020 kernel/fork.c:2090

The buggy address belongs to the physical page:
page:ffffea000062fd80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x18bf6
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 3595, tgid 3595 (syz-executor.0), ts 845488137720, free_ts 845392226828
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2533
 prep_new_page mm/page_alloc.c:2540 [inline]
 get_page_from_freelist+0x32ed/0x3480 mm/page_alloc.c:4292
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5559
 vm_area_alloc_pages mm/vmalloc.c:2979 [inline]
 __vmalloc_area_node mm/vmalloc.c:3047 [inline]
 __vmalloc_node_range+0x96c/0x1460 mm/vmalloc.c:3219
 alloc_thread_stack_node kernel/fork.c:311 [inline]
 dup_task_struct+0x3e5/0x6d0 kernel/fork.c:980
 copy_process+0x637/0x4020 kernel/fork.c:2090
 kernel_clone+0x222/0x920 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2820 [inline]
 __se_sys_clone kernel/fork.c:2804 [inline]
 __x64_sys_clone+0x231/0x280 kernel/fork.c:2804
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1460 [inline]
 free_pcp_prepare mm/page_alloc.c:1510 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3388
 free_unref_page_list+0x107/0x810 mm/page_alloc.c:3530
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 __pagevec_release+0x80/0xf0 mm/swap.c:1075
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 truncate_inode_pages_range+0x48a/0x1340 mm/truncate.c:373
 kill_bdev block/bdev.c:76 [inline]
 blkdev_flush_mapping+0x154/0x2b0 block/bdev.c:662
 blkdev_put_whole block/bdev.c:693 [inline]
 blkdev_put+0x4c0/0x750 block/bdev.c:953
 blkdev_close+0x56/0x80 block/fops.c:514
 __fput+0x3b7/0x890 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffffc90003ba7700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90003ba7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90003ba7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffffc90003ba7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90003ba7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/29 19:57 linux-6.1.y a343b0dd87b4 cf184559 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-6-1-kasan KASAN: out-of-bounds Write in end_buffer_read_sync
2023/08/12 06:29 linux-6.1.y 1321ab403b38 39990d51 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan KASAN: out-of-bounds Write in end_buffer_read_sync
2024/04/03 11:38 linux-6.1.y e5cd595e23c1 7925100d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: out-of-bounds Write in end_buffer_read_sync
2024/03/29 13:03 linux-6.1.y e5cd595e23c1 c52bcb23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: out-of-bounds Write in end_buffer_read_sync
2023/11/02 12:28 linux-6.1.y 4a61839152cc 69904c9f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: out-of-bounds Write in end_buffer_read_sync
2024/01/07 23:56 linux-6.1.y 38fb82ecd144 d0304e9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: out-of-bounds Write in end_buffer_read_sync
* Struck through repros no longer work on HEAD.